Question

To earn a “B” in Probability, Sara must get a grade average of at least 80%. Sara’s test scores are 85, 90, and 75. Her final exam score counts as three test scores in the average. Sara got a grade of 78 on the final exam. What was her final grade average? Did she get a “B”?

Answer 1

ANSWER:

80.67$

She get a B

STEP-BY-STEP EXPLANATION:

We must calculate the weighted average, in this case, each note is multiplied by its weight and divided by the sum of the total of the weights, like this:

$\begin{gathered} a=\frac{85\cdot1+90\cdot1+75\cdot1+78\cdot3}{1+1+1+3} \\ a=\frac{85+90+75+234}{6}=\frac{484}{6}=80.67 \end{gathered}$

The final grade average is 80.67%, which means that Sara got a B.